Lightweight Peat's Mucky Muck soil testing

[biggreg]

Again if my volume of soil weight is less than standard does my weight of amendments stay the same?

The elements you amend are tested on a per weight (mass) basis.

Mass of your element per dry kilo Is diffrent but related to your mass of element per Volume.


Your plant needs certain amount of these elements per your volume. That doesn't change with density.

Luckily, peat and organic matter have high exchange capicity ( per mass) and can hold onto similar amounts of elements as lower exchange capacity ( per mass) mineral soil. Both can have similar per volume exchange capacity.

The relevant unit of exchange capacity is per volume. Meq/100cm3 not /100g

In mineral soil you can say a soil has 20meq/100g or 20meq/100cm3 because it's 1g/cm3 bulk density.

 

[biggreg]

g/cm3=BD ?

Bulk density is oven dried mass in grams per field-moist volume.

Or how much it weighs dry per a volume of its actual moist working volume.

g/cm3

It's usually expressed in oven dried mass / field moist volume

The relevant units for working with this Mechlich 3 that calls for an air dried sample would be air-dried mass per field moist volume.

Air dried soil has more mass per volume than oven dried by a bit. Not sure if it matters that much or not.

 

[acespicoli]

agreed thanx

 

[acespicoli]

Specific problems that might be caused by poor function: High bulk density is an indicator of low soil porosity and soil compaction. It may cause restrictions to root growth, and poor movement of air and water through the soil. Compaction can result in shallow plant rooting and poor plant growth, influencing crop yield and reducing vegetative cover available to protect soil from erosion. By reducing water infiltration into the soil, compaction can lead to increased runoff and erosion from sloping land or waterlogged soils in flatter areas. In general, some soil compaction to restrict water movement through the soil profile is beneficial under arid conditions, but under humid conditions compaction decreases yields.

 

[_tessarecting]

What do you do once you've taken moist and dry weight? Forgive me I am a layman when it comes to math but am trying to grasp this concept. I know it will affect my fertilizer input amounts but how exactly if it's not a multiplication of (eg. .4) to the calculated mineral numbers in the worksheets?

Also are any of you guys requesting anything different from your labs to improve accuracy or are we all kinda SOL right now

 

[acespicoli]

Also I think we looked into CEC* earlier in this thread in relation to BD?

 

[biggreg]

Here is the crux of my whole issue:

With under-measured sample mass from a wrongly calibrated spoon, you might as well throw your carefully weighed and measured bulk density and toss it in the shit can.

The report is skewed. Using an accurate Bulk Density become pointless.

You get no where amending this way. The way it would work with a proper test.

The work around is to use 1g/cm3 as a density just like you would for "standard" density field soil.

The reason the "cheat" works is our mixes usually have similar exchange capacities per VOLUME as field soils. But one can't get very precise especially in lower range or higher range CEC mixes.

 

[biggreg]

What do you do once you've taken moist and dry weight? Forgive me I am a layman when it comes to math but am trying to grasp this concept. I know it will affect my fertilizer input amounts but how exactly if it's not a multiplication of (eg. .4) to the calculated mineral numbers in the worksheets?

Also are any of you guys requesting anything different from your labs to improve accuracy or are we all kinda SOL right now

The dry mass/ moist volume
(g/cm3 bulk density)
Is used to convert grams needed of your amendment per the dry mass of your soil.


I've called a shit load of labs all across the country and asked if they would measure the mass of my lightweight soil with a balance vs a wrong soil class calibrated scoop. Earlier in the thread I listed a few labs that have no problem doing it

I've got a sample I'm waiting on the results on sent to exact scientific labs in WA. I've learned that labs there and in BC never use a scoop to weigh anything.

I also have this lab measuring the bulk density the air dried to thier spec/ field moist volume.

They agreed to do a custom report on per mass and per volume.

Maybe will hear back today?

Trying them out.

 

[biggreg]

I got good impressions talking with:

MB labs in BC. NEVER SCOOPS

Exact scientific in WA. NEVER SCOOPS

Waters Ag in North Carolina. They seemed
up to custom reports. They are familiar with the NCDA method.

Rockriver labs scoops but was willing to weigh in the mass of the sample no extra charge.

Logan told me no
Brookside said no
Spectrum charged me extra to weigh in but there seemed to be a misunderstanding and it came out they only use 1g for all their tests. Not happy about that.

 

[biggreg]

On the soil to solution ratio.

Ol' Man Mechlich published his method as 2.5cm3 soil per 25ml of his special sauce.
All results reported in volume only. He didn't test per mass.
He designed his test as universal. Heavy 1.5g/cm3 sand to the usually .4gto .6g but sometimes.2g/cm3 peaty backlands organic soils. His method includes a bulk density and soil class determination of organic ( peaty) min-organic ( mixed peat with mineral soil) or mineral. Im looking to get with Waters Ag in NC to do a NCDA style volume only test but with a custom report and a few add ons in units that would be relevant to us.



The usda soil survey Kellog lab takes that original Mechlich recipe to mean 2.5cc at 1g/1cm3 "standard" soil or 2.5g soil to 25ml solution. This reports in per mass.

The exact scientific lab is running the per mass test for me at 2.5g soil per 25ml solution.


The 4 regional methods manuals have all agreed to a 2g to 20ml standard. Same ratio as the original. Just less soil to test.

No written standard i could find reduces it further to 1g per 10ml. None.

So my project is a per mass test done to original Mechlich ratio of 2.5 to 25. With a bulk density test and dual reports in per mass and per volume.

And then

The volume scoop, modified NCDA style with a 2.5cm3 scoop and 25ml. Report in volume only.

Not sure which way is the way to go.

 

[acespicoli]

What do you do once you've taken moist and dry weight? Forgive me I am a layman when it comes to math but am trying to grasp this concept. I know it will affect my fertilizer input amounts but how exactly if it's not a multiplication of (eg. .4) to the calculated mineral numbers in the worksheets?

Also are any of you guys requesting anything different from your labs to improve accuracy or are we all kinda SOL right now

What size container you growing in?

 

[acespicoli]

Saturated Media Extract (SME) is the test im looking into now I dont just want EC and PH I want the NPK with secondaries and micros. Waiting for a lab reply now...

 

[_tessarecting]

Approx 2 yard mounds.

Im getting 5 tests done this week and am going to try to balance it for the first time myself as much as i can

 

[biggreg]

Saturated Media Extract (SME) is the test im looking into now I dont just want EC and PH I want the NPK with secondaries and micros. Waiting for a lab reply now...

That is a test of the soil solution today

The Mechlich is a test of how your buffer is charged. Potential plant nutrients complexed into your humus and clay, your soil reserves.

Use both. Use the M3 to figure grams of that K you need.

I don't mean to confuse you with my bitch-fest meant for growers who are familiar with this test. The test is solid and workable in its bastard form.

The satty paste test won't tell you the grams of potash you need. It will tell you to pour more bottled, soiluble k on it.

 

[acespicoli]

Exactly biggreg I think its going to work well for me not everyone, just in the case of green house container grown weekly test for ph and ec. I want the lab to run that solution for nutes, what do you think is that possible? Long term release im not worried about my grows end in 8 weeks.

 

[acespicoli]

Approx 2 yard mounds.

Im getting 5 tests done this week and am going to try to balance it for the first time myself as much as i can

Do you have a ppm result or pound per acre recommendation?

 

[acespicoli]

I mix 20 gallons of soil at a time on a tarp and fill 4 pots 5 gallon each.
The conversion has to match volumes of field space or containers
Field volumes are 6 inch till depth for added fertilizers?

 

[biggreg]

Exactly biggreg I think its going to work well for me not everyone, just in the case of green house container grown weekly test for ph and ec. I want the lab to run that solution for nutes, what do you think is that possible? Long term release i not worried about my grows end in 8 weeks.

8 weeks will drain your "long term" supply of elements held in your buffer quickly dependent on container size.

Also the chemical balance is important. Look back at mulder's chart you pasted into this thread.

15-20 $ for a M3 and you can balance that no K soil.

If I were gonna steer by satty paste only, I'd get one every week. Or get the equip to test soil solution myself weekly

 

[acespicoli]

8 weeks will drain your "long term" supply of elements held in your buffer quickly dependent on container size.

Also the chemical balance is important. Look back at mulder's chart you pasted into this thread.

15-20 $ for a M3 and you can balance that no K soil.

If I were gonna steer by satty paste only, I'd get one every week. Or get the equip to test soil solution myself weekly

Thats whats up buddy!
Your right about that a 5 gallon does not last long on nutes
Also you make a good point on balance thats where those hydro calc excel sheets come in handy

Just adding one nute can affect others I have seen it in tests now I understand it in theory

 

[biggreg]

I mix 20 gallons of soil at a time on a tarp and fill 4 pots 5 gallon each.
The conversion has to match volumes of field space or containers
Field volumes are 6 inch till depth for added fertilizers?

Forget till depth pounds per acre shit.

Work in ppm and liters then covert to gallons at the end. Easy

Thing with this stuff is, at least for me, complicated until you do a couple of your own soil prescriptions and it will be super simple.

It's a learn by doing. It's way easier than it sounds or reads.